Semiconductor Integrated Device Having Solid-State Image Sensor Packaged Within and Production Method for Same

ABSTRACT

A semiconductor integrated device comprises: a light-shielding film which shields at least some part of a transfer section of the semiconductor integrated device from light; a first wiring formed in the same layer as the light-shielding film, with one end connected to a pad electrode and an other end extended to a side edge of the semiconductor substrate; a second wiring arranged to go around a side face of the semiconductor substrate, and connected to the first wiring; and a sealing member which seals the solid-state image sensor.

TECHNICAL FIELD

The present invention relates to a semiconductor integrated devicehaving a solid-state image sensor packaged within and a productionmethod for the same.

BACKGROUND ART

Recently, chip size packages have been widely used in order tominiaturize the chip size of solid-state image sensors.

Firstly, a solid-sate image sensor is described here. FIG. 10 is a planview showing the construction of a solid-state image sensor.

A solid-state image sensor, in the case of a frame transfer type forexample, is essentially composed of a light receiving section 200, astorage section 202, a horizontal transfer section 204, an outputsection 206 and an output amplifier 208. The light receiving section 200has a plurality of light receiving pixels arranged in a matrix, andstores information charges, which are generated in response to receivinglight, in each respective light receiving pixel. The storage section 202has a plurality of storage pixels arranged according to the number oflight receiving pixels of the light receiving section 200, and takes inand temporarily stores information charges of one image stored in thelight receiving section 200. The horizontal transfer section 204 takesin information charges from the storage section 202 in units of oneline, and transfers them horizontally one pixel at a time. The outputsection 206 converts the information charges transferred from thehorizontal transfer section 204 to voltage value and outputs them inunits of one pixel. The output amplifier 208 amplifies the voltage valueoutputted from the output section 206, and outputs it as an imagesignal.

A solid-state image sensor having such a construction has a diffusionlayer on the semiconductor substrate surface and electrodes arranged onthe substrate, and comprises the light receiving section 200, thestorage section 202, the horizontal transfer section 204, the outputsection 206 and the output amplifier 208, and lastly has alight-shielding film, which blocks light, arranged in all areas exceptfor the light receiving section 200 (the hatched area in the diagram).

Next, a semiconductor integrated device in which a chip-sized package isapplied for the solid-state image sensor is described. FIG. 11 is across-sectional view of the semiconductor integrated device cut along aposition corresponding to the line X-X in FIG. 10.

A P-type diffusion layer 302 is, formed on the surface of an N-typesemiconductor substrate 300, and an N-type diffusion layer 304 is formedin this P-type diffusion layer 302. Highly concentrated P-typeimpurities are implanted in places in the N-type diffusion layer 304,and a channel stopper (not shown) is formed. Then, a transfer electrode306 is formed on the semiconductor substrate 300 having an insulationfilm 305 in between, and the solid-state image sensor is formed.

An insulation film 308 is laminated on the transfer electrode 306, and avoltage supply line 310 and a pad electrode 322 are formed on thisinsulation film 308. This voltage supply line 310 and pad electrode 322are electrically connected to the transfer electrode 306 via a contactformed in the insulation film 308. Moreover, an insulation film 312 islaminated on the voltage supply line 310 and the pad electrode, and aninternal wiring 314 is formed on the insulation film 312. This internalwiring 314 is, on its cross-sectional surface, connected to an externalwiring 110 arranged along the side face of the package. An insulationfilm 316 is laminated on the internal wiring 314, and a light-shieldingfilm 318 is arranged in the area covering the storage section 202, thehorizontal transfer section 204 and the output section 206 on thisinsulation film 316. Then, a surface protection film 320, covering thelight-shielding film 318 and the insulation film 316, is formed.

DISCLOSURE OF THE INVENTION

The contact resistance of the connection place, between the internalwiring 314 of the sensor and the external wiring 110, needs to be keptsufficiently low. Usually, the thickness of the voltage supply line isapproximately 1 μm, and as this thickness is insufficient to directlyconnect to the external wiring 110, an additional internal wiring 314having greater thickness has needed to be provided.

In this case, since an additional process for forming the internalwiring 314 is required, production throughput of the solid-state imagesensor is reduced, and the problem of a rise in production cost hadarisen.

Also, the end part of the internal wiring 314 can easily become corrodedfrom outside the sensor and there has been the problem of a reduction inthe strength of the connection with the external wiring 110 whencorroded.

In consideration of the problems of the conventional art mentionedabove, an object of the present invention is to provide a semiconductorintegrated device that is capable of solving at least one ofabovementioned issues, and that does not undermine the characteristicsof the sensor, and that can be formed easily; and a production methodfor the same.

The present invention is a semiconductor integrated device comprising: asolid-state image sensor having on a semiconductor substrate, a lightreceiving section which receives light and generates informationcharges, and a transfer section which transfers information chargesstored in the light receiving section; and wherein a voltage is suppliedthrough a pad electrode arranged along one edge of the semiconductorsubstrate; a light-shielding film which is formed on the semiconductorsubstrate and which shields at least some part of the transfer sectionfrom light; a first wiring formed in the same layer as thelight-shielding film, with one end connected to the pad electrode and another end extended to a side edge of the semiconductor substrate; asecond wiring arranged to go around a side face of the semiconductorsubstrate, and connected to the first wiring; and a sealing member whichseals the solid-state image sensor.

Another aspect of the present invention is characterized in that in aproduction method for a semiconductor integrated device in which an endpart of a first wiring extends to a side edge of a solid-state imagesensor, and in which this first wiring is connected to a second wiringarranged to go around a side face of the solid-state image sensor, themethod includes: a first process in which a light receiving sectionwhich receives light and generates information charges, and a transfersection which transfers information charges stored in the lightreceiving section, are formed, and then the solid-state image sensor isformed on the semiconductor substrate; a second process in which alight-shielding film which shields at least the transfer section, isformed on the semiconductor substrate, and the first wiring is formed inthe same layer as the light-shielding film; and a third process in whichthe second wiring is formed and connected to the first wiring.

Another aspect of the present invention is characterized in that in aproduction method for a semiconductor integrated device in which an endpart of an internal wiring extends to a side edge of a solid-state imagesensor, and in which this internal wiring is connected to an externalwiring arranged to go around a side face of the solid-state imagesensor, the method includes: a first process in which a light receivingsection which receives light and generates information charges, and atransfer section which transfers information charges stored in the lightreceiving section, are formed, and then the solid-state image sensor isformed on the semiconductor substrate; a second process in which a padelectrode which supplies voltage to the light receiving section and tothe transfer section, is formed while a first internal wiring is formedin the same layer as the pad electrode; a third process in which alight-shielding film which shields at least the transfer section, isformed on the semiconductor substrate while the second internal wiringwhich overlaps the first internal wiring, is formed in the same layer asthe light-shielding film; and a fourth process in which an externalwiring is formed and then the first internal wiring and the secondinternal wiring are connected.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view showing the cross-sectional construction of asemiconductor integrated device of an embodiment of the presentinvention.

FIG. 2A and FIG. 2B are perspective views showing the package appearanceof the semiconductor integrated device of the embodiment of the presentinvention.

FIG. 3 is a flow chart illustrating a production method for thesemiconductor integrated device of the embodiment of the presentinvention.

FIG. 4 is a diagram illustrating a production process of thesemiconductor integrated device of the embodiment of the presentinvention.

FIG. 5 is a diagram illustrating the production process of thesemiconductor integrated device of the embodiment of the presentinvention.

FIG. 6 is a diagram illustrating the production process of thesemiconductor integrated device of the embodiment of the presentinvention.

FIG. 7 is a diagram illustrating the production process of thesemiconductor integrated device of the embodiment of the presentinvention.

FIG. 8 is a diagram illustrating the production process of thesemiconductor integrated device of the embodiment of the presentinvention.

FIG. 9 is a diagram illustrating the production process of thesemiconductor integrated device of the embodiment of the presentinvention.

FIG. 10 is a plan view showing the construction of a conventionalsolid-state image sensor.

FIG. 11 is a view showing the cross-sectional construction of aconventional semiconductor integrated device.

BEST MODE FOR CARRYING OUT THE INVENTION

In connection with describing an embodiment of the present invention,firstly, the basic construction of a semiconductor integrated devicehaving a solid-state image sensor packaged within is described.

FIG. 2A and FIG. 2B are perspective views showing one example of asemiconductor integrated device in which a chip-sized package is appliedfor the solid-state image sensor. A solid-state image sensor chip 104 issealed between resin films 106, between a first and a second glasssubstrate 100 and 102. A plurality of ball-shaped terminals 108 arearranged on the main face of the second glass substrate, that is, theback side of the device, and these ball-shaped terminals 108 areconnected to the solid-state image sensor chip 104 via an externalwiring 110. A plurality of the external wirings 110 are connected towirings drawn out from the so id-state image sensor chip 104, andestablish contacts with each respective ball-shaped terminal 108.

Next, the embodiment of the invention of the present application isdescribed. FIG. 1 is a view showing the cross-sectional construction ofthe semiconductor integrated device of the embodiment of the inventionof the present application. FIG. 1 is a cross sectional view of asemiconductor integrated device cut at a position corresponding to theline X-X of FIG. 10. The same reference symbols are given toconstructions the same as those shown in FIG. 2A, FIG. 2B, FIG. 10 andFIG. 11.

A P-type diffusion layer 302 is formed on an N-type semiconductorsubstrate 300, and an N-type diffusion layer 304 is formed in thisP-type diffusion layer 302. Highly dense P-type impurities are partiallyimplanted in the N-type diffusion layer 304 and a channel stopper (notshown) is formed. Then, a transfer electrode 306 is arranged on thesemiconductor substrate 300 having the insulation film 305 in between.

An insulation film 308 is laminated on the transfer electrode 306, and avoltage supply line 310 and a first internal wiring 407 are formed onthis insulation film 308. This voltage supply line 310 and firstinternal wiring 407 are formed in the same layer, and of these, thefirst internal wiring 407 is formed at the end part on the peripheryside of the package.

A second internal wiring 414 and a light-shielding film 418 are arrangedon the voltage supply line 310, an pad electrode 322 and the firstinternal wiring 407, having an insulation film 312 in between. Thesecond internal wiring 414 is formed extending from a predeterminedposition to the end part of the package, and is made to connect to thefirst internal wiring 407 at the end part of the package. Moreover, thesecond internal wiring 414 is connected to an external wiring 110 whereit overlaps with the first internal wiring 407. A light-shielding film418 is arranged to cover the area of the storage section 202, thehorizontal transfer section 204 and the output section 206, and itprevents light from entering to the storage section 202, the horizontaltransfer section 204 and the output section 206. An insulation film 420is laminated on the light-shielding film and the second internal wiring414, and also, a first glass substrate 100 is arranged above them,sandwiching the resin film 106 in between.

According to this kind of construction, the contact area of the externalwiring 110 and the internal wiring becomes greater compared to that ofthe conventional construction, so that the connection strength betweenthe external wiring 110 and the internal wiring can be improved. Also,since the second internal wiring 414 that constitutes part of theinternal wiring is formed in the same layer as the light-shielding film418, the second internal wiring 414 can be formed at the same time whileusing the forming process of the light-shielding film 418. Consequently,the connection strength between the external wiring 110 and the internalwiring can be improved without incurring additional production process.

Furthermore, materials generally used for semiconductor devices, such assilver, gold, copper, aluminum, nickel, titanium, tantalum, andtungsten, may be used as the chief material for the voltage supply line310, the pad electrode 322 and the light-shielding film 418. When takinginto account electrical resistance value and processability of material,it is preferable to employ aluminum. Also, the end parts of the firstinternal wiring 407 and the second internal wiring 414 can easily becomecorroded from outside the sensor, and in order to avoid such corrosion,it is more preferable to employ aluminum containing copper in a range noless than 0.1 atomic percent and no more than 20 atomic percent.

Since the minimum process line width of the electrode needs to be keptsmall and the electrical resistance value needs to be kept sufficientlylow, it is preferable that the thickness of the voltage supply line 310and the pad electrode 322 be made no less than 0.5 μm and no more than 2μm. Moreover, it is even more preferable that it be made no less than0.5 μm and no more than 1 μm.

On the other hand, since the light-shielding film 418 does not require aminimum process line width made that small, and needs to sufficientlyblock unwanted light, it can be made thicker than the voltage supplywiring layer. Taking into account the throughput of the productionprocess, it is preferable that it be made no less than 1.5 μm and nomore than 8 μm when aluminum is the chief material. Moreover, it is evenmore preferable that it be made no less than 2.0 μm and no more than 8μm.

Specifically, the total thickness of the first internal wiring 407 andthe second internal wiring 414, which is the connection point with theexternal wiring, is preferably made no less than 2 μm at the least andno more than 10 μm, and thus, the connection strength can be improvedwhile the contact resistance when connected to the external wiring 110on the side face of the solid-state image sensor is kept low, at thesame level as that of the conventional internal wiring 314.

FIG. 3 is a flow chart describing a production method for thesemiconductor integrated device of the invention of the presentapplication, and FIG. 4 to FIG. 9 are cross-sectional views of thesemiconductor integrated device, corresponding to each productionprocess.

In step S10, the light receiving section 200 which is a sensor section,the storage section 202, the horizontal transfer section 204 and theoutput section 206 are formed. Firstly, P-type impurity ions areimplanted and diffused in the surface of the N-type semiconductorsubstrate 300 a in wafer condition, and a P-type semiconductor area 302is formed. Then, N-type impurity ions are implanted and diffused in theP-type semiconductor area 302 and an N-type semiconductor area 304 isformed. Then, the insulation film 305 and the transfer electrode 306 areformed on the semiconductor substrate 300 a by appropriately combiningdeposition techniques such as sputtering and a chemical vapor phasegrowth method, and photolithography techniques. Then, highlyconcentrated P-type impurity ions are implanted in parts of thesemiconductor area 304 to form the channel stopper (not shown), and thestate as shown in FIG. 4 is reached.

In step S12, the peripheral circuit of the output amplifier 208 isformed in the area near the sensor section as shown in FIG. 5. Formingthe peripheral circuit can be carried out in the same manner as theconventional process for forming a transistor.

For example, a source area and a drain area are formed by means ofdoping techniques such as thermal diffusion and ion implantation, and athermally-oxidized film which becomes a gate insulation film is formedby means of thermal oxidation. Then, a polysilicon layer or a metalfilm, which becomes a source electrode (not shown), a drain electrode(not shown) and a gate electrode, are formed by combiningphotolithography techniques and deposition techniques such as a chemicalvapor phase growth method.

In step S14, the voltage supply line 310 and the first internal wiring407 are formed as shown in FIG. 6. A metal layer, which becomes thevoltage supply line 310 that transmits externally supplied voltage, isformed. At the same time, the first internal wiring 407 is also formedmaking use of the metal layer.

Specifically, the interlayer insulation film 308 upon which the voltagesupply line 310 and the first internal wiring 407 are to be formed, isformed on the semiconductor substrate 300 a. Then, aperture holes areprovided in necessary places on the interlayer insulation film 308 bymeans of a photolithography technique, and the metal layer is formed bymeans of a deposition technique such as sputtering or a chemical vaporphase growth method. Then, the voltage supply line 310 and the firstinternal wiring 407 are formed by patterning the metal layer.

For example, the metal layer can be formed by means of aluminumsputtering. In this case the voltage supply line 310 and the firstinternal wiring 407 can be formed to have high resistance to corrosionby employing aluminum containing no less than 0.1 atomic percent and nomore than 20 atomic percent of copper as the target material.

Furthermore, the voltage supply line 310 and the first internal wiring407 can also be formed by using deposition. In this case, the voltagesupply line 310 and the first internal wiring 407 can be formed to havehigh resistance to corrosion by employing aluminum containing no lessthan 0.1 atomic percent and no more than 20 atomic percent of copper asthe material at this point.

Furthermore, the voltage supply line 310 and the first internal wiring407 can be formed using a chemical vapor phase growth method. In thiscase, an aluminum film containing no less than 0.1 atomic percent and nomore than 20 atomic percent of copper and having high corrosionresistance can be formed by adjusting the proportions of a mix of anorganic gas containing aluminum and an organic gas containing copper.

In step S16, the light-shielding film 418 and the second internal wiring414 are formed as shown in FIG. 7.

Firstly, the interlayer insulation film 312 is formed. Then, apertureholes are provided in necessary places on the sensor section and theperipheral circuit by means of a photolithography technique or similar,and the metal layer is formed by means of a vapor deposition techniquesuch as sputtering or a chemical vapor phase growth method. Then, thesecond internal wiring 414 and the light-shielding film 418 are formedby patterning the metal layer.

At this point, as with the voltage supply line 310, it is preferable toform the metal layer by means of sputtering, vapor deposition or achemical vapor phase growth method, and to form an aluminum film,containing no less than 0.1 atomic percent and no more than 20 atomicpercent of copper, and having a high resistance to corrosion.

In step S20, the first and second glass substrates 100 and 102 areadhered by the resin films 106 as shown in FIG. 8. In the process ofthis step S20, for example, epoxy resin is generally used to adhere theglass plates.

In step S22, the external wiring 110 is formed as shown in FIG. 9.Firstly, an inverted V groove is formed by cutting from the second glasssubstrate 102 side using a tapered dicing saw, and the first and secondinternal wiring 407 and 414 are exposed out of the inner face of thegroove. Then, a metal layer is formed on the inner face of the groove bymeans of sputtering, vapor deposition, or a chemical vapor phase growthmethod, and the external wiring 110 is formed by pattering this metallayer. After this, the ball-shaped terminals 108 are formed so as toconnect to the external wiring on the surface of the second glasssubstrate 102.

In step S24, the laminate formed in step S22 is diced along the scribeline; that is, the border line of each solid-state image sensor. As aresult, the semiconductor integrated device is completed.

As described above, according to the production method for thesemiconductor integrated device of the present embodiment, since thelight-shielding film 418 and the internal wiring are formed in the sameprocess, the process of forming the internal wiring can be omittedcompared to in the conventional production method. Consequently, theproduction process can be simplified, and the solid-state image sensorpackage can be efficiently produced. Also, since internal wiring isformed in two stages for the first and second internal wirings 407 and414, and has a two-layer construction, the connection strength with theexternal wiring 110 can be improved.

According to the present invention, in a semiconductor integrated devicein which the internal wiring is connected to the external wiringarranged along the side face of the package, a semiconductor integrateddevice, for which the production process can be simplified withoutundermining the characteristics of the sensor, and a production methodfor the same can be provided.

Furthermore, although a frame transfer type solid state image sensor wasindicated as the example for this embodiment, it is not limited to this.For example there is ample possibility for application withsemiconductor integrated devices using interline type or frame-interlinetype solid state image sensors too.

1. A semiconductor integrated device comprising: a solid-state imagesensor having on a semiconductor substrate, a light receiving sectionwhich receives light and generates information charges, and a transfersection which transfers information charges stored in said lightreceiving section; and wherein a voltage is supplied through a padelectrode arranged along one edge of said semiconductor substrate; alight-shielding film which is formed on said semiconductor substrate andwhich shields at least some part of said transfer section from light; afirst wiring formed in the same layer as said light-shielding film, withone end connected to said pad electrode and an other end extended to aside edge of said semiconductor substrate; a second wiring arranged togo around a side face of said semiconductor substrate, and connected tosaid first wiring; and a sealing member which seals said solid-stateimage sensor.
 2. A semiconductor integrated device according to claim 1,wherein said first wiring has at least two layers, and at least one ofthese at least plurality of layers is formed in the same layer as saidlight-shielding film.
 3. A semiconductor integrated device according toclaim 2, wherein in said first wiring at least one layer is formed inthe same layer as said pad electrode.
 4. A semiconductor integrateddevice according to claim 1, wherein said first wiring comprisesaluminum containing copper.
 5. A semiconductor integrated deviceaccording to claim 1, wherein said first wiring has a film thickness ofno less than 2.0 μm and no more than 10 μm. 6-9. (canceled)